Date: Thu, 23 Sep 1999 11:31:47 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
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To: djgpp-workers AT delorie DOT com
Subject: Re: FSDB broken in CVS version?
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While working on the FSDB bug that Andris reported in this thread, I
found a couple of unrelated problems:

 - F8 (step over) doesn't work if it uses INT3 to place a temporary
   breakpoint after the function call.  To reproduce, set 4 or more
   breakpoints in various places of a program (so that FSDB runs out
   of debug registers), and then press F8 until you come to a CALL
   instruction.  You will see an error message when you try to step
   over that CALL.

 - FSDB didn't know about SIGQUIT.

 - The message about unexpected Int 3 was misplaced.

These problems are not new, even v2.01 had them.  The patches are
below.


*** src/debug/fsdb/fullscr.c~1	Tue Sep 21 21:46:02 1999
--- src/debug/fsdb/fullscr.c	Wed Sep 22 19:55:54 1999
*************** typedef enum { R_Step, R_Step1, R_Over, 
*** 1021,1027 ****
  static void
  step (KIND_TYPE kind)
  {
!   int i, b, no, len, int03hit;
    char *inst = 0;
    int tracing = (kind == R_Step1);
    word32 final = -1;
--- 1021,1027 ----
  static void
  step (KIND_TYPE kind)
  {
!   int i, b = -1, no, len, int03hit;
    char *inst = 0;
    int tracing = (kind == R_Step1);
    word32 final = -1;
*************** step (KIND_TYPE kind)
*** 1103,1109 ****
        user_screen ();
        b = set_breakpoint (BP_Code, 0, final);
        go (1);
-       reset_breakpoint (b);
        break;
      case R_Run:
        user_screen ();
--- 1103,1108 ----
*************** step (KIND_TYPE kind)
*** 1123,1128 ****
--- 1122,1129 ----
    if ((int03hit = (i == 0x03)
         && get_breakpoint (BP_Code, 0, a_tss.tss_eip - 1) != -1))
      a_tss.tss_eip--;  /* point back to Int 3 */
+   if (kind == R_Over && b >= 0)
+     reset_breakpoint (b);  /* reset only after get_breakpoint did its thing */
    if (tracing) return;
  
    /* Find out whether a breakpoint stopped us.  */
*************** step (KIND_TYPE kind)
*** 1204,1214 ****
  	message (CL_Error, "User program used debug registers");
        else if (i == 1 && (edi.dr[6] & (1 << 15)))
  	message (CL_Error, "Task switch caused debug exception");
-       else if (i == 3 && !int03hit)
- 	message (CL_Error, "Unexpected Int 3 hit");
      }
    else if (i == 0x79 || i == 0x09)
      message (CL_Info, "Keyboard interrupt");
    else if (i == 0x75)
      {
        char *reason;
--- 1205,1217 ----
  	message (CL_Error, "User program used debug registers");
        else if (i == 1 && (edi.dr[6] & (1 << 15)))
  	message (CL_Error, "Task switch caused debug exception");
      }
+   else if (i == 3 && !int03hit)
+     message (CL_Error, "Unexpected Int 3 hit");
    else if (i == 0x79 || i == 0x09)
      message (CL_Info, "Keyboard interrupt");
+   else if (i == 0x7a)
+     message (CL_Info, "QUIT key pressed");
    else if (i == 0x75)
      {
        char *reason;